I don't mean this to be a "wise-ass" question but in all seriousness,
why would it matter whether the film was reversed or not (so that Twain
was walking from left to right or from right to left, or whatever).  It
is such a small snippet with so little happening in it, I honestly find
it hard to conceive what of interest can be found in Zapruder-like
analysis of this film clip.  Again, not meaning this as an insult to
those who are deeply interested in analysis of the clip -- I'm just
honestly wondering what or why.  Yes, I know it's the only known film
clip of Twain.  But that kind of footage -- brief, choppy, silent, etc.
-- just "is what it is" and what it is seems to me not much!

Now, analyzing Twain's words in that recently published piece in the New
Yorker about how social constraints and our need for the approval of
others constrains our ability to express ourselves freely during our
lifetimes -- that contains so many more clues to Twain that this film
clips' buttons on the coat, drinking tea with one hand or the other,
etc.  IMHO.

Steve Hoffman
Takoma Park MD